IxiT ^'*ot€s to Introductonj Lecture. 



2. Thej do not contain any uric acid, nor any combination 

 of this acid with the alkalis. The defect of uric acid in those 

 urines, struck Mr. Vauquelin more forcibly, as he used to 

 ascribe its formation to animal food. 



3. They contain only a very small quantity of muriate of 

 soda, (sea salt,) whereas that of man contains a great deal. 

 ■\Ve find in these urines, much urea, phosphates of soda and 

 of ammonia, sulphate of potash, mucous matter, and a trace 

 of iron. The urine of the beaver has a great resemblance 

 to the urine of herbiverous animals ; that of a rabbit, con- 

 tains lime, magnesia, and carbonate of potash, sulphates of 

 potash and of lime, muriate of potash, urea, gelatine, and 

 sulphur. He did not find any soda in the urines of the ca- 

 mel, cow, Guinea pig, or rabbit. The urine of the horse, 

 according toFourcroy and Vauquelin, (Thompson's Chemis- 

 try, vol. 4,) contains carbonates of lime and of soda, much 

 benzoat of soda, muriate of potash, and urea. Mr. Brande's 

 analysis of the horse's urine, agrees with that of Messrs. 

 Fourcroy and Vauquelin, but he also found in it sulphate of 

 soda, muriate of soda, but no urea, potash or ammonia. Mr. 

 Brande found that the urine of the ass contains a much great- 

 er relative proportion of the phosphat of lime and urea, also 

 carbonate, sulphate, and muriate of soda, and a small quan- 

 tity of potash. The urine of both the horse and ass is des- 

 titute of ammonia. 



The foregoing details of the urine of various animals are 

 given, as being connected with the interests of agriculture ; 

 urine having been found to be highly stimulant to vegeta- 

 bles : and from the abundance of certain ingredients in that 

 of a particular animal, and their deficiency in others, we 

 may ascertain why certain urines are prejudicial, or useful 

 to particular plants. 



JS'^ote 41. 



The notion of the submersion of swallows during winter is 

 of Swedish origin. Glaus, the bishop of Upsal first promul- 

 gated it, and naturalists more worthy of attention assented 



